Process for the separation of alcohol from the first runnings



F eb.28, 1939. 'E voN RETZE E-r AL PROCESS FOR THE SEPARATION OF ALCOHOL FROM THE FIRST RUNNINGS Filed Feb. 1, 1957 w. W w

Patented Feb. 28, 1939 sms TENT

reis

PROCESS FR THE SEPARATION F ALCO- HOL FROM THE FIRST RUNNINGS Goldund Silber` Schcideanstalt, vormals Roessler, Frankfort-on-the-Main, Germany Application February 1,1937, Serial No. 123,514

' In Switzerland April 11, 1936 6 Claims.

This invention relates to improvements in the separation of alcohol from the first runnings obtained in the distillation of alcohol.

It has been found that the acetaldehyde and the other first run products of alcohol distillation processes cannot be separated from the alcohol quantatively by simple distillation, although the acetaldehyde and other rst run products have a substantially lower boiling point than alcohol. Experience has shown that it is extremely'difcult to separate the lower boiling constituents from the alcohol by distillation sincethe vapour pressure of the lower boiling constituents such as aldehydes are considerably lowered in the presence of alcohol and for this reason such compounds are retained by the alcohol to a considerable extent. This is particularly true for the last portions of the lower boiling constituents. There-A l run fraction. According to experience, to 10% and even more of the alcohol must be distilled over with the lower boiling products in order to insure complete removal of the aldehydes. This means that a relatively large portion of the alcohol is obtained in a less valuable form.

In. the past it has been proposed to facilitate the separation of alcohol from the rst run fraction by introducing hot water at the upper part of the alcohol distillation column. However, the results,k obtainable by such a procedure are limited and it is` only possible to reduce the amount of alcohol carried over by the first run fraction to about 5% of the alcohol or slightly less. In this proposed method, dilution of the raw spirit causes prohibitive heat requirements and because of this only relatively poor results could be obtained. Aside from this the proposed method is imprac# tical as the introduction of large quantities of Water at the top of the fractionating column renders the separation of the higher alcohols by fractionation impossible.

According to the present invention it is possible to secure substantially complete separation of alcohol from the rst run fraction in a very simple manner by first distilling orf all the lower boiling products, together with the alcohol carried over thereby and then passing this first run fraction 'into a separate column4 wherein the 4vapours.

boiling point of the alcohol.

(ci. 2oz-40) atomized condition, if necessary. All of the alcohol is thereby washed out of the rst run fraction and the resulting dilute alcohol may then be returned to the distilling column for the concentration of the alcohol thus obtained.

principle is applicable to the present process,l

such as, bubble columns, Raschig columns and the like.- However, it is also possible toI employ empty columns when the water is introduced in an atomized state vinto the upper portion thereof. The temperatures of the warm water may range between the boiling point of the lower boiling constituents of the first run fractions and the That is, the ternperature must be suiciently high to vaporize the lower boiling constituents but low enough to prevent the alcohol from passing oi with the vapours of these products at the top of the column. The temperature of the water, however, must be regulated with a View to other conditions in the washing column as for instance the heat which may be supplied by heat exchange elements in the lower portion thereof and the rate of flow of the rst fractions which are introduced into Ithe column and their temperature.

The advantages of the new process reside in the fact that it is possible to separate off substantially one hundred per cent of the lower boiling products while practically all of the alcohol maybe converted into fine high grade spirits, and in add-ition, the new process may be carried out with a very low consumption of heat as the warm water' supplied to the washing column may be first still water or water from condensers.

The new process may be carried out advantageously either periodically or continuously. The rst run fraction passes off at' the upper part of the alcohol distillation `column and is intro- 'duced into the lower portion of a washing columnl either as a vapor or as a liquid, while warm water is introduced at the upper portion of the column and cause to flow Adownwardly and countercurrently to vapours of the first run fraction. The quantity of water introduced into the washundistilled product, and distilling of! the alcohol from such' product. l

5. The process of reining crude. spirits which comprises fractionating the crude spirits in a fractionating column, drawing off iirst run frac' tion at the head ofl the fractionating column,A drawing of! nespirits below the headV of the column, drawing oi fusel oils below the point at which the ilne spirits are withdrawn, scrubbing the ilrst run traction while in vaporized i'orm with warm water in a separate column whereby the alcohol carried over in the rst run fraction is washed out. drawing oi! the remaining constituents of the rst run fraction in the vapor phase and returning the ensuing dilute alcohol directly to the fractionating column at a. point below the above-mentioned points at which the distillation products are withdrawn.

y6. In a process as claimed in claim l, the warm water being supplied in an amount suicient to produce an alcohol solution of 40% to 70% concentration. v

' EWALD von REIZE.

FRIEDO FLGGE. 

